Not come across this pattern before, but have seen a Calcutta Police Badge of similar shape and design cast in white metal. Of two part cast construction with two long screw posts to revise of a presumably for fitting on to a brass fireman's helmet. it comes with a small button to the same unit, circa 16mm in diameter. Both in good condition and worn from 1901 until circa 1949.Please note that on account of depth of screw posts I will only post to a UK address.Comm TeMo